KR101469761B1 - Calculation Method and Apparatus of Underwater Acoustic Radiation Pattern of the Ship by Separate Calculation of Radiation Pattern and Total Radiation Power - Google Patents

Abstract

The present invention relates to a technique for detecting an underwater acoustic radiation pattern. More particularly, the present invention relates to a method of calculating an underwater acoustic radiation pattern, which predicts remote underwater noise radiated to a medium near an acoustic radiator due to surface resonance of the acoustic radiator having a large size and a complex shape and moving at sea/underwater, in a three-dimensional pattern; and to an apparatus thereof.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for calculating a radiation pattern of a ship by a radiation pattern and a total radiation power separation,

The present invention relates to a technique for predicting an underwater radiated noise pattern, and more particularly, to a method for predicting a radiated radiated noise radiated to a surrounding medium of a radiant body in a three-dimensional pattern due to surface vibrations of a complex- And to a method and an apparatus for calculating an underwater radiated noise pattern.

Generally, in the hull of a ship, a large number of apparatuses for generating vibrations such as pumps and the like (hereinafter referred to as "vibration generating bodies") are installed, as well as various types of engine facilities. The vibrations generated from these vibration generators are transmitted to the hull as they are, and noise is generated from the outside of the hull, and it propagates through the medium contacting with the outside of the hull as noise, which is called Underwater Radiated Noise (URN).

A method of calculating radiation noise using a Helmholtz Integral Equation equation or a Rayleigh Integral Equation using numerical integration techniques such as BEM (Boundary Element Method) and FEM (Finite Element Method) By measuring the average vibration velocity and calculating the total total radiated noise using the radiation efficiency of the surface of the acoustic radiator, the cross-spectrum of the vibration velocity of the surface elements of the radiator and the radiation efficiency of each of the surface elements of the radiator, A method of calculating radiation noise at an arbitrary point, and the like are known.

In the first method, the prediction accuracy is high, but the calculation time is long, and it is almost impossible to predict the radiated noise of the large-sized noise radiator such as a ship in real time.

The second method is a calculation method for the total amount of radiated acoustic energy, and it does not include directivity information of acoustic radiation.

In the third method, the radiation efficiency value of each radiator surface element is required. However, it is difficult to measure all the radiation efficiency of a large radiator surface element having a complicated shape such as a trap.

1. Korean Patent No. 10-1357763

1. Son Kwon, "Underwater Target Reflection Signal Energy Restoration Technique Using Independent Component Analysis Technique" Kyungpook National University, 2012. 2. Seo Youngsoo et al., "Experimental Investigation of Airborne and Underwater Vibration of FRP Structures", Proceedings of KSNVE 2012 Spring, 2012.

The present invention has been proposed in order to solve the problems according to the above background art, and it has been proposed to transmit a far-water radiated noise radiated to a surrounding medium of a radiator to a three-dimensional pattern by a surface vibration of a complicated- And to provide a method and an apparatus for calculating an underwater radiated noise pattern of a trap that can be predicted by the method.

The present invention also relates to a method of dividing a surface of an acoustic radiator into a plurality of vibration field elements (hereinafter referred to as " surface patches ") by a user, A method and apparatus for calculating underwater radiated noise patterns of a ship which calculates the radiation noise direction as well as the total radiated noise power in the prediction of underwater radiation noise by calculating the approximate radiation efficiency characteristic value in a practical and accurate three dimensional radiation noise pattern There are other purposes to provide.

In order to achieve the above-mentioned object, the present invention provides a method of predicting a radiated noise radiated to a surrounding medium of a radiator in a three-dimensional pattern due to surface vibration of a complicated shaped large noise radiator moving in the sea and / A method for calculating an underwater radiated noise pattern is provided.

The method for calculating the underwater radiated noise pattern,

a) the speed of the emitter surface patches according to the characteristics of the emitter surface of the emitter is divided into a plurality of emitter surface patches, and a plurality of speed sensors distributed by emitter surface patches are used, Measuring the total radiative efficiency of the radiator;

b) measuring the velocity of the plurality of emitter surface patches in any state to be predicted;

c) calculating radiated noises using the Helmholtz equation using the velocities of the plurality of radial surface patches as input, calculating a normalized original sound field radiation pattern by dividing the radiation noise for each patch by the radiated noise sum value ;

d) calculating a total radiated noise power for each of the plurality of emitter surface patches using the radiator gross radiative efficiency; And

e) calculating the underwater radiated noise power for each of the original sound field patches using the total radiated sound power and the normalized original sound field radiation pattern.

In this case, when calculating the radiation noise, the step (c) may be performed by applying the plane wave condition of the surface pressure of the acoustical radiator and the full radiation condition of the plurality of the radiator surface patches.

In addition, it is preferable that any one of the steps c), d), and e) does not perform the measurement of the radiation efficiency for each of the plurality of emitter surface patches, and performs normalization using only the measured velocities of the plurality of surface patches The radiation sound power of the original sound field patch can be predicted by calculating the original sound field radiation pattern in advance and using the total radiation noise power as a correction term.

(여기서,

는 근접 음장 측정을 통한 총 방사소음 파워,

는 원음장 매질의 밀도,

는 원음장 매질의 음속,

는 원음장 패치의 총면적,

는 방사체 표면의 진동 속도 제곱의 평균값,

는

번째 방사체 표면 패치의 속도를 나타낸다)에 의해 산출되는 것을 특징으로 할 수 있다.Further, the total radiation efficiency of the radiator is expressed by Equation

(here,

The total radiated noise power through the near field measurement,

The density of the original sound field medium,

The sound velocity of the original sound field medium,

The total area of the original sound patch,

Is the mean value of the oscillation velocity square of the emitter surface,

The

Lt; th > radiator surface patch) of the first radiator surface patch.

The normalized original sound field radiation pattern is calculated by measuring the velocities of the plurality of emitter surface patches, calculating the surface pressure by applying the full emission condition of the emitter surface patch, and then calculating the original sound field emission noise. can do.

Further, the method of calculating the underwater radiation noise pattern may further include calculating a three-dimensional radiation noise pattern using the radiation noise power per the original sound field patch after the step (e).

The radiation noise power for each of the original sound field patches may be calculated by multiplying the normalized original sound field radiation pattern and the total radiation noise power generated in the original sound field by the vibration.

On the other hand, another embodiment of the present invention includes a plurality of velocity sensors, which divide the emitter surface of the acoustic radiator into a plurality of emitter surface patches and are distributedly installed by emitter surface patches; A radiation efficiency calculation unit for calculating the approximate radiation efficiency of the emitter by measuring the near field of the vicinity of the emitter surface patch and the velocity of the emitter surface patch according to the characteristics of the plurality of velocity sensors; Calculating a radiated noise using the Helmholtz equation which measures and inputting the velocities of the plurality of emitter surface patches in an arbitrary state to be predicted, and calculating a radiation pattern to calculate the original sound field radiation pattern by normalizing the calculated radiated noise part; A power calculator for calculating a total radiated noise power for each of the plurality of emitter surface patches using the radiator total approximate radiation efficiency; And an underwater radiation noise pattern calculation unit for predicting the radiation noise power per original sound field patch using the total radiation noise power and the normalized original sound field radiation pattern. The present invention provides an apparatus for calculating the underwater radiated noise pattern of a ship.

According to the present invention, it is possible to measure in real time the vibrational velocity of a moving radiator surface element and effectively calculate a three-dimensional underwater radiated noise pattern.

In addition, as another effect of the present invention, it is unnecessary to measure the radiation efficiency of each of the surface elements of the radiator, which is difficult to measure in the calculation of the radiation noise pattern, and the normalized radiation noise pattern precedence calculation And the method of correcting the radiation pattern using the total radiation noise power calculation value is introduced to efficiently predict the underwater radiation noise of the moving marine / underwater noise emitting body in real time.

1 is a conceptual diagram of N emitter surface patches and a original sound field patch used in accordance with an embodiment of the present invention.
2 is a conceptual diagram of a M original sound field patch used in accordance with an embodiment of the present invention.
FIG. 3 is a flowchart illustrating a process of calculating a radiation pattern of a ship through a radiation pattern and total radiation power separation calculation according to an embodiment of the present invention.
4 is a block diagram illustrating the construction of an underwater radiated noise pattern apparatus 400 according to an embodiment of the present invention.
FIG. 5 is an explanatory diagram of a 62 original sound field patch as an example shown in FIG.
6 is a graph showing the calculation result of the underwater radiated noise pattern at 250 Hz according to an embodiment of the present invention.
7 is a graph showing the calculation result of the underwater radiation noise pattern at 1750 Hz according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Should not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and an apparatus for calculating an underwater radiation noise pattern of a ship through a radiation pattern and total radiation power separation calculation according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram of N emitter surface patches 130 and far-field patches 120 used in accordance with one embodiment of the present invention. 1, there is a radiating surface 140 by an acoustic radiator (not shown), and a Far-field surface 110 having a radiator surface 140 as a sphere, Field-side patches 120. The far-field-field patches 120 are formed of a plurality of patches. The underwater radiated noise prediction plane is defined as a spherical surface and is divided into a plurality of original sound field elements (hereinafter referred to as a 'original sound field patch') to display radiated noise patterns.

2 is a conceptual diagram of a M original sound field patch used in accordance with an embodiment of the present invention.

번째 방사체 표면 패치(130)의 면적과 속도는

,

이 된다.FIG. 3 is a flowchart illustrating a process of calculating a radiation pattern of a ship through a radiation pattern and total radiation power separation calculation according to an embodiment of the present invention. Referring to FIG. 1 and FIG. 2, a Far-field surface 110 in the form of a sphere is divided into M original sound field patches 120, If you divide into

The area and velocity of the first emitter surface patch 130

,

.

이다(단계 S310,S311,S312). Also, the total total acoustic power generated by the vibration at the original sound field is

(Steps S310, S311, S312).

The noise emitted from the emitter surface patch 130 is expressed by the Helmholtz Integral Equation as the following equation.

)에서의 음압,

는 방사체 표면패치(

)에서의 표면음압,

은 방사체 표면 요소의 수직벡터,

는 그린함수(Green function,

)이다.Here, P is an arbitrary point on the sound source prediction plane (

),

Lt; RTI ID = 0.0 >

),

Is the vertical vector of the emitter surface element,

(Green function,

)to be.

When the far-field condition is applied, equation (1) is expressed by the following equation.

은 방사체 표면 패치

로부터 원음장 예측 지점

까지의 거리,

은 총 방사체 표면 패치 개수,

는 방사체 표면 패치의 수직벡터와 방사체 표면 패치로부터 R을 잇는 선이 이루는 각,

는 방사체 표면 패치의 표면 압력을 나타낸다.here,

The emitter surface patch

To the original sound field prediction point

The distance to,

The total emitter surface patch number,

Is the angle between the vertical vector of the radiator surface patch and the line connecting the radiator surface patch to R,

Represents the surface pressure of the radiator surface patch.

)을 측정하면 원음장 패치(120)에서의 소음수준이 계산되나 실제 수중에서 움직이는 방사체 표면에서의 음압을 측정하는 것은 불가능하다. Surface pressure

), The noise level at the original sound field patch 120 is calculated, but it is impossible to measure the sound pressure at the surface of the moving radiator in actual water.

)을 다음식으로 대치하여 방사체 표면에 부착된 가속도 센서로부터 측정 가능한 표면 속도를 포함한다(단계 S320).Therefore, in the embodiment of the present invention, when calculating the radiation noise, assuming the full radiation condition in the emitter surface patch 130,

(Step S320), which is measured from an acceleration sensor attached to the radiator surface.

는

번째 표면패치의 근접음장 음향파워,

는 표면 압력,

는

번째 방사체 표면 패치(130)의 면적,

는

번째 방사체 표면 패치(130)의 속도,

는 원음장 매질의 밀도,

는 원음장 매질의 음속을 나타낸다.here,

The

Of the first surface patch, sound field acoustical power,

Surface pressure,

The

The area of the first radiator surface patch 130,

The

The speed of the first emitter surface patch 130,

The density of the original sound field medium,

Represents the sound velocity of the original sound field medium.

번째 표면패치의 진동 에너지이며 좌변은 방사체 표면 패치(도 1의 130)의 근접 음장으로 방사된 총 음향 에너지이다. 위 수학식 3을 수학식 2에 대입하여 원음장 패치에서의 방사소음 파워를 나타내면 다음식과 같이 표현된다. The right side of Equation (3)

Th surface patch and the left side is the total acoustic energy radiated to the near field of the emitter surface patch (130 in FIG. 1). Equation (3) is substituted into Equation (2) and the radiation noise power in the original sound field patch is expressed as follows.

은 i번째 방사체 표면 패치

로부터 원음장 예측 지점

까지의 거리를 나타낸다.here,

Lt; RTI ID = 0.0 > i <

To the original sound field prediction point

.

번째 원음장 패치(120)의 방사소음 파워(W_k)는 다음식과 같이 계산된다. From the above equation (4)

The radiation noise power (W _k ) of the first original sound field patch 120 is calculated by the following equation.

는

번째 원음장 패치(120)의 면적을 나타낸다. here,

The

Th original sound field patch.

)으로 나누어 정규화된 원음장 패치별 방사소음 파워(

)는 다음식과 같이 표현된다. Therefore, the sum of radiation noise power per patch (

) And the normalized radiation noise power of the original sound field patch (

) Is expressed by the following equation.

는 k번째 원음장 패치(120)의 방사소음 파워이다.here,

Is the radiated noise power of the k-th original sound field patch 120.

)을 입력하여 위 수학식 4 및 수학식 6으로부터 우선적으로 방사패턴을 계산한다. Vibration velocity measurement value (Vibration velocity value per surface patch measured above,

), And the radiation pattern is first calculated from the above Equations (4) and (6).

)를 분리 계산하여 보정함으로써 함정의 수중 방사 소음 패턴을 산출한다. At the same time, the total radiated noise power

) Is calculated and corrected to calculate the underwater radiated noise pattern of the ship.

)와 방사체 표면 패치(130)에서 계측된 평균 진동 속도 변화를 이용하여 방사체 전체 방사효율(

)를 계산하면 식 7과 같이 표현된다(단계 S330).Total Radiated Noise Power through Near Field Measurement

) And the average vibration velocity change measured at the radiator surface patch 130,

) Is calculated as shown in Equation 7 (Step S330).

는 근접 음장 측정을 통한 총 방사소음 파워,

는 원음장 매질의 밀도,

는 원음장 매질의 음속,

는 원음장 패치(120)의 총면적,

는 방사체 표면(140)의 진동 속도 제곱의 평균,

는

번째 방사체 표면 패치(130)의 속도를 나타낸다.here,

The total radiated noise power through the near field measurement,

The density of the original sound field medium,

The sound velocity of the original sound field medium,

The total area of the original sound field patch 120,

The average of the oscillation velocity squares of the emitter surface 140,

The

Lt; RTI ID = 0.0 > 130 < / RTI >

)는 다음식과 같이 표현된다(단계 S340).Using the above equation (7), the total radiated noise power

Is expressed as the following equation (step S340).

)는 식 9와 같이 계산되고 3차원 수중 방사소음 패턴을 구할 수 있다(단계 S350).If the total radiated noise power of Equation (8) is used as a correction term for radiated noise per patch on the normalized radiation pattern calculation result of Equation (6), the radiated noise power per original sound field patch

Is calculated as shown in Equation 9 and a three-dimensional underwater radiated noise pattern can be obtained (Step S350).

는 정규화된 원음장 패치별 방사소음 파워,

는 진동에 의하여 원음장에서 발생되는 총 방사 소음 파워를 나타낸다.here,

Is the radiation noise power per normalized original sound field patch,

Represents the total radiated noise power generated in the original sound field by vibration.

는 도 2의 각 패치별 방사소음 파워 값이므로 도 2의 예측면에서 3차원 방사소음 패턴이 구해진다.(원음장 패치별 방사소음 파워 = 3차원 방사소음 패턴)

2 is a radiation noise power value for each patch of FIG. 2, so that a three-dimensional radiation noise pattern is obtained from the prediction plane of FIG. 2. (Radiation noise power per one sound field patch = three-dimensional radiation noise pattern)

4 is a block diagram illustrating the construction of an underwater radiated noise pattern apparatus 400 according to an embodiment of the present invention. 4, an underwater radiation noise pattern apparatus 400 includes a plurality of velocity sensors 410-1 to 410-4 that divide the emitter surface of the acoustic radiator 401 into a plurality of emitter surface patches and are distributedly installed by emitter surface patches -n), a speed sensor (140-1 to 140-n) which detects the speed of the patch by the emitter surface patches according to characteristics of the plurality of speed sensors (410-1 to 410- A radiation efficiency calculation unit 430 for calculating a total radiation efficiency of the radiator by measuring the radiation intensity, a radiation noise calculation unit 430 for calculating a radiation noise using a Helmholtz equation, which measures and inputs the velocities of the plurality of emitter surface patches in an arbitrary state to be predicted, A radiation pattern calculation unit 420 for calculating the radiation pattern of the original sound field by normalizing the calculated radiation noises, A power calculation unit 440 for calculating a total radiated noise power with respect to the star speed, and an underwater radiated noise pattern calculation for predicting the radiated noise power per original sound field patch using the total radiated sound power and the normalized original sound field radiation pattern 450 and the like.

The plurality of speed sensors 410-1 to 410-n are constituted by an acceleration and / or a speed sensor.

FIG. 5 is an explanatory diagram of a 62-piece original sound field patch as an example shown in FIG. 2. FIG.

6 is a graph showing the calculation result of the underwater radiation noise pattern when the frequency of the acoustic radiator (401 in FIG. 4) is 250 Hz according to an embodiment of the present invention. Referring to FIG. 6, there is shown the actual measured value 610 and the predicted value 620 according to an embodiment of the present invention, according to the number of original sound field patches.

FIG. 7 is a graph showing the calculation result of the underwater radiation noise pattern when the frequency of the acoustic radiator (401 in FIG. 4) is 1750 Hz according to an embodiment of the present invention. Referring to FIG. 7, the magnitude of the original sound field pressure according to the number of original sound field patches is shown as an actual measured value 710 and a predicted value 720 according to an embodiment of the present invention.

400: Underwater radiation noise pattern calculation device
401: acoustic radiator
410: sensor array
420: radiation pattern calculation unit
430: Radiation efficiency calculation unit
440: Power calculation unit
450: underwater radiation noise pattern calculation unit

Claims (7)

a) the speed of the emitter surface patches according to the characteristics of the emitter surface of the emitter is divided into a plurality of emitter surface patches, and a plurality of speed sensors distributed by emitter surface patches are used, Measuring the total radiative efficiency of the radiator;
b) measuring the velocity of the plurality of emitter surface patches in any state to be predicted;
c) calculating radiated noises using the Helmholtz equation using the velocities of the plurality of emitter surface patches as inputs, and calculating a normalized one-sided radiation pattern by dividing the radiated noise for each patch by the radiated noise sum value;
d) calculating a total radiated noise power for each of the plurality of emitter surface patches using the radiator gross radiative efficiency; And
e) calculating the underwater radiated noise power per original sound field patch using the total radiated sound power and the normalized original sound field radiation pattern;
And calculating a total radiation power separation calculation based on the radiation patterns.
The method according to claim 1,
Wherein the calculation of the radiation noise is performed by applying a plane wave condition of a surface pressure of the acoustical radiator and a complete radiation condition of the plurality of radiator surface patches to calculate a total radiation power separation calculation Method of calculating underwater radiated noise pattern of a ship through.
The method according to claim 1,
Wherein any one of steps c), d), and e) does not perform measurements on the radiation efficiency for each of the plurality of emitter surface patches, but uses only the measured velocities of the plurality of surface patches, Calculating a radiation pattern by predicting the radiation noise power of the original sound field patch by predicting the radiation pattern and using the total radiation noise power as a correction term, .
The method according to claim 1,
The overall radiation efficiency of the radiator is given by Equation

(here,

The total radiated noise power through the near field measurement,

The density of the original sound field medium,

The sound velocity of the original sound field medium,

The total area of the original sound patch,

≪ / RTI > is the average of the oscillating velocity squares of the emitter surface,

The

Wherein the first and second radiator surface patches are indicative of the velocity of the first radiator surface patch. ≪ RTI ID = 0.0 > 11. < / RTI >
The method according to claim 1,
Wherein the normalized original sound field radiation pattern is calculated by measuring the velocities of the plurality of emitter surface patches and calculating the surface pressure by applying full emission conditions of the emitter surface patches and then calculating the original sound field radiation noise. A method for calculating underwater radiated noise pattern of a ship by calculating the pattern and total radiation power separation.
The method according to claim 1,
Wherein the radiation noise power of each of the original sound field patches is calculated by multiplying a normalized original sound field radiation pattern and a total radiation noise power generated in a original sound field by vibration. Method of calculating underwater radiated noise pattern.
A plurality of velocity sensors that divide the emitter surface of the acoustic radiator into a plurality of emitter surface patches and are distributedly installed by emitter surface patches;
A radiation efficiency calculation unit for calculating the approximate radiation efficiency of the emitter by measuring the near field of the vicinity of the emitter surface patch and the velocity of the emitter surface patch according to the characteristics of the plurality of velocity sensors;
A radial noise is calculated using a Helmholtz equation which measures and inputs the velocities of the plurality of emitter surface patches in an arbitrary state to be predicted, and a radiation pattern for calculating the original sound field radiation pattern by normalizing the calculated radiation noise Calculating section; A power calculator for calculating a total radiated noise power for each of the plurality of emitter surface patches using the radiator total approximate radiation efficiency;
An underwater radiation noise pattern calculation unit for predicting the radiation noise power per original sound field patch using the total radiation noise power and the normalized original sound field radiation pattern;
And calculating a total radiation power separation calculation based on the radiation patterns.

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